Dual beam projection lamp mount construction



April 18, 1967 G. H. BURNETT 3,315,112

DUAL BEAM PROJECTION LAMP MOUNT CONSTRUCTION Filed Dec. 28, 1964 ITWVfiiTYTCDTI George H. Burne b t D9 @1 2: ff

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United States Patent 3,315,112 DUAL BEAM PRGJECTION LAMP MOUNT CONSTRUCTION George H. Burnett, Cleveland Heights, Ohio, assignor to General Electric Company, a corporation of New York Filed Dec. 28, 1964, Ser. No. 421,499 Claims. (Cl. 313-115) This invention relates generally to electric incandescent lamps, and more particularly to high intensity projection lamps of the so-called sealed beam type comprising a reflector section and containing a pair of filaments arranged to provide selectively a concentrated spot beam or a spreading flood beam. Such lamps are useful for photographic home movie lighting or similar purposes and are operable at relatively high voltage.

It is an object of the invention to provide a mount structure for supporting the filaments which is of rugged construction. It is a further object to provide a structure including filament supports arranged in a novel manner to avoid destructive arcing between points of high electrical potential on the filaments and their supporting structure, particularly when the lamp is designed for operation at a potential of 240 volts, for example. It is a further object to provide a structure which will be rugged even with the incorporation of a relatively weak fuse section in one of the lead wires, particularly a common lead wire through which both of the filaments are energized.

The invention will best be understood by reference to the following detailed description taken in conjunction withv the drawing wherein:

FIG. 1 is a perspective view of a'lamp structure comprising the invention with the bulb broken away through the reflector section;

FIG. 2 is a front elevation view of the lamp structure shown in FIG. 1;

FIG. 3 is a side elevation of the lamp shown in section along the line 3-3 in FIG. 2; and

FIG. 4 is a fragmentary section along the line 4-4 in FIG. 2 showing the fused common lead and associated supporting structure.

Referring to FIG. 3 of the drawing, the lamp comprises a sealed gas-filled bulb comprising a reflector section 1 of pressed glass and a pressed cover glass or lens section 2 fused together at their peripheries, the reflector section 1 being provided on its inner surface with a. reflecting coating 3 which may be of aluminum or silver, for example. The refiector section 1 is preferably of generally paraboloidal contour with a horizontal axis indicated by the broken line 4. The said reflector section 1 is. pro vided with three lead wire openings 5, 6 and 7 arranged about its apex and its axis 4, to be approximately at the corners of a triangle, which may be an isosceles triangle, with the first and second openings 5 and 6, respectively, tit-opposite sides of said apex and axis 4, and in a horizontal plane including said axis 4, and the third opening 7 above said horizontal plane and preferably in a vertical plane including said axis 4. Each of the openings 5, 6 and 7 is closed by a metal'thimble 8, 9 and 1t respectively, having a feathered edge hermetically sealed and embedded in the glass around the margin of the respective opening.

Three lead wires 11, 12 and 13 have their outer ends anchored in respective thimbles 8, 9 and 18, preferably by a quantity of bnazing material 14 therein, and they project through respective associated openings 5, 6 and 7 into the interior of the reflector section 1, preferably parallel to each other and to the reflector axis 4. T he first lead wire 11 includes a fuse section 15 (FIG. 4) adjacent its outer end, with a rigid insulating sleeve 16, preferably of ceramic material, spanning said fuse section 3,315,112 Patented Apr. 18, 1967 15 and closely fitting the sections of the lead wire 11 interrupted by the fuse 15. The sleeve restores rigidity to the lead wire 11 which would otherwise flex rather readily at the fuse section 15 which is of relatively smaller and more flexible wire or alloy as is well known in the Mt.

An auxiliary fourth lead wire 17 is connected, preferably by welding, at one end to the first lead wire 11 and extends laterally therefrom to the vertical plane including the reflector axis 4 and to a point below the horizontal plane including said axis 4 with its free end 17a extending parallel to said axis 4 and in alignment with the third lead wire 13. The said fourth lead wire 17 is preferably Welded to the first lead wire 11 at a point to engage one end of the ceramic sleeve 16 to thereby firmly confine said sleeve between the said wire 17 and the body of brazing material 14 in thimble 8.

A first helically coiled, preferably coiled-coil, filament 18 of tungsten wire extends horizontally between and is connected to the first and second lead wires 11 and 12 and is preferably substantially centered about the focus of the reflector section 1 on the axis 4. A second helically coiled, preferably coiled-coil, filament 19 extends vertically between and is connected to the third lead wire 13 and to the free end 17a of the auxiliary fourth lead wire 17; said filament 19 being located behind the filament 13 and behind the focus of the reflector section 1.

The mount assembly is rigidified by an insulating glass bridge member 20 which extends laterally between and is secured at one end to the second lead wire 12 and at its other end to the auxiliary fourth lead wire 17 adjacent its free end. The glass bridge 20 is preferably secured to the respective lead wires by pairs of wire studs 21 and 22 each having one end embedded in the bridge 20 and their other ends welded to the respective lead wires. The lead wire 17 is thereby firmly supported, and the lead wire 11 additionally supported, particularly against torsional weakness of the fuse section 15, by virtue of the bridge connection 20.

The filaments 18 and 19 are also additionally supported by auxiliary support wires 23 and 24 respectively. Each said support wire 23 and 24 has one end embedded in the glass bridge 20 and has its free end formed to engage and support the respective filament 18 or 19 at its midpoint, preferably by a hook portion formed at the extremity of the support wire. The support wire 23 extends generally parallel to the reflector axis 4 and then laterally to the midpoint of filament 18. The support wire 24 extends angularly toward the midpoint of filament 19. It will be noted that support wire 23 is anchored adjacent the end of bridge 21 near the second lead wire 12 carrying the filament 18 which is supported by said Wire 23; and the support wire 24 is anchored adjacent the end of said bridge 20 near the fourth lead Wire 17 which carries the filament 19 which is supported by said wire 24. Thereby, the said filament supports 23 and 24 are located in positions of lowest voltage potential, and arcing over between the supports, the filaments and the lead wires is avoided.

In a particular lamp of the type illustrated herein, the coiled-coil filaments 18 and 19 may be so designed that each consumes 650 watts. Thereby, a concentrated spot beam is provided by the filament 18 which is at the focus of the reflector section 1, whereas energization of the filament 19 provides a spreading flood beam because of its location behind the reflector focal point. It will be evident that, if desired, the. reflector contour and the location of the filaments may be such that one of the filaments is located at the focal point and the other is located in front of the focal point rather than behind it.

The bulb 1, 2 is evacuated and gas-filled with an inert gas such as nitrogen, for example, in conventional manner through an aperture 25 at the apex and through an exhaust:

3 tube extending therefrom, the sealed or tipped-off residue of the exhaust tube being shown at 26 (FIG. 3).

There is also shown in the drawing a heat deflector or shield 27 which may be made of sheet nickel metal, for example. The said shield 27 is welded to the lead wire 12 to extend transversely of the reflector axis 4 so as to be in a vertical position behind filament 19 during operation of the lamp. Due to the high wattage of filament 19, there is a flow of extremely intensive convection currents upward around the filament which, together with the radiant energy projected from the filament, causes a severe overheating of the reflector in the vicinity of the opening 7 which can result in destruction of the reflective coating around said opening and a pocketing of the heat sufficient to deform the glass around said opening and to cause cracks in the seal between the thimble 10 and the glass. Such action is prevented by the shield 27 which deflects the heat away from said opening 7 and thimble it). This subject matter is not claimed herein, but is claimed in application Ser. No. 421,498 of George H. Burnett and Emmett H. Wiley, filed of even date herewith.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A dual beam projector lamp comprising a sealed glass bulb having a concave generally paraboloidal reflector section and a light-transmitting cover glass section and adapted for use with the reflector axis horizontal; said reflector section having three lead wire openings arranged about its apex to be approximately at the corners of a triangle with a first and second of said openings at opposite sides of said apex and in a horizontal plane including said reflector axis and the third opening above said horizontal plane and in a vertical plane including said reflector axis; metallic thimble members at the exterior of said reflector section having their edges fused in the glass around the margins of respective said openings; first, second and third lead wires having their outer ends anchored in respective said thimbles and projecting through the associated first, second and third openings into the interior of said reflector section; said first lead wire including a fuse section adjacent its outer end with a rigid insulating sleeve spanning said fuse section and closely fitting the lead wire; and an auxiliary fourth lead wire connected at one end to the first lead wire and extending laterally therefrom to the said vertical plane including the reflector axis at a point below said horizontal plane with its other free end in alignment with the third lead wire; a rigid insulating glass bridge member extending laterally between and secured at one end to the second lead wire and at its other end to said auxiliary fourth lead wire adjacent its said free end; a first coiled filament extending horizontally between and connected to said first and second lead wires and substantially centered about the focus of said reflector section; a second coiled filament extending vertically between and connected to said third lead wire and to the said free end of said auxiliary fourth lead wire and located behind the said focus of the reflector section; a first support Wire having one end embedded in said glass bridge adjacent the end thereof near said second lead wire and having its other free end formed to engage and support said first filament approximately at its midpoint; and a second support wire having one end embedded in said glass bridge adjacent the end thereof near said auxiliary fourth lead wire and having its free end formed to engage and support said second filament approximately at its midpoint.

2. A dual beam projector lamp comprising a sealed glass bulb having a concave generally paraboloidal reflector section and a light-transmitting cover glass section and adapted for use with the reflector axis horizontal; said reflector section having three lead wire openings arranged about its apex to be approximately at the corners of a triangle with a first and second of said openings at opposite sides of said apex and in a horizontal plane including said reflector axis and the third opening above said horizontal plane and in a vertical plane including said reflector axis; metallic thimble members at the exterior of said reflector section having their egdes fused in the glass around the margins of respective said openings; first, second and third lead wires having their outer ends anchored in respective said thimbles and projecting through the associated first, second and third openings into the interior of said reflector section; and an auxiliary fourth lead wire connected at one end to the first lead wire and extending laterally therefrom to the said vertical plane including the reflector axis at a point 'below said horizontal plane with its other free end in alignment with the third lead wire; a rigid insulating glass bridge member extending laterally between and secured at one end to the second lead wire and at its other end to said auxiliary fourth lead wire adjacent its said free end; a first coiled filament extending horizontally between and connected to said first and second lead wires and substantially centered about the focus of said reflector section; a second coiled filament extending vertically between and connected to said third lead wire and to the said free end of said auxiliary fourth lead wire and located behind the said focus of the reflector section; a first support wire having one end embedded in said glass bridge adjacent the end thereof near said second lead wire and having its other free end formed to engage and support said first filament approximately at its midpoint; and a second support wire having one end embedded in said glass bridge adjacent the end thereof near said auxiliary fourth lead wire and having its free end formed to engage and support said second fila ment approximately at its midpoint.

3. A dual beam projector lamp comprising a sealed glass bulb having a concave generally paraboloidal reflec tor section and a light-transmitting cover glass section and adapted for use with the reflector axis horizontal; said reflector section having three lead wire openings arranged about its apex to be approximately at the corners of a triangle with a first and second of said openings at opposite sides of said apex and in a horizontal plane including said reflector axis and the third opening above said horizontal plane and in a vertical plane including said reflector axis; metallic thimble mem-- bers at the exterior of said reflector section having their egdes fused in the glass around the margins of respective said openings; first, second and third lead wires having their outer ends anchored in respective said thimbles and projecting through the associated first, second and third openings into the interior of said reflector section; said first lead wire including a fuse section adjacent its outer end with a rigid insulating sleeve spanning said fuse section and closely fitting the lead wire; and an auxiliary fourth lead wire connected at one end to the first lead wire and extending laterally therefrom to the said vertlcal plane including the reflector axis at a point below said horizontal plane with its other free end in alignment with the third lead wire; a rigid insulating glass bridge member extending laterally between and secured at one end to the second lead wire and at its other end to said auxiliary fourth lead wire adjacent its said free end; a first coiled filament extending horizontally between and connected to said first and second lead wires and substantially centered about the focus of said reflector section; and a second coiled filament extending vertically between and connected to said third lead wire and to the said free end of said auxiliary fourth lead wire and located behind the said focus of the reflector section.

4. A dual beam projector lamp comprising a sealed glass bulb having a concave generally paraboloidal reflector section and a light-transmitting cover glass section and adapted for use with the reflector axis horizontal; said reflector section having three lead wire openings arranged about its apex to be approximately at the corners of a triangle with a first and second of said openings at opposite sides of said apex and in a horizontal plane including said reflector axis and the third opening above said horizontal plane and in a vertical plane including said reflector axis; metallic thimble members at the exterior of said reflector section having their egdes fused in the glass around the margins of respective said openings; first, second and third lead wires having their outer ends anchored in respective said thimbles and projecting through the associated first, second and third openings into the interior of said reflector section; and an auxiliary fourth lead Wire connected at one end to the first lead wire and extending laterally therefrom to the said vertical plane including the reflector axis at a point below said horizontal plane with its other free end in alignment with the third lead wire; a rigid insulating glass bridge member extending laterally between and secured at one end to the second lead wire and at its other end to said auxiliary fourth lead wire adjacent its said free end; a first coiled filament extending horizontally between and connected to said first and second lead wires and substantially centered about the focus of said reflector section; a second coiled filament extending vertically between and connected to said third lead wire and to the said free end of said auxiliary fourth lead wire and located behind the said focus of the reflector section.

5. A dual beam projector lamp comprising a sealed glass bulb having a concave generally paraboloidal reflector section and a light-transmitting cover glass section and adapted for use with the reflector axis horizontal; said reflector section having three lead wire openings arranged about its apex to be approximately at the corners of a triangle with a first and second of said openings at opposite sides of said apex and in a horizontal plane including said reflector axis and the third opening above said horizontal plane and in a vertical plane including said reflector axis; metallic thimble members at the exterior of said reflector section having their edges fused in the glass around the margins of respective said openings; first, second and third lead wires having their outer ends anchored in respective said thimbles and projecting through the associated first, second and third openings into the interior of said reflector section; said first lead wire including a fuse section adjacent its outer end with a rigid insulating sleeve spanning said fuse section and closely fitting the lead Wire; and an auxiliary fourth lead wire connected at one end to the first lead wire and extending laterally therefrom to the said vertical plane including the reflector axis at a point below said horizontal plane with its other free end in alignment with the third lead wire; a rigid insulating glass bridge member extending laterally between and secured at one end to the second lead wire and at its other end to said auxiliary fourth lead wire adjacent its said free end; a first coiled filament extending horizontally between and connected to said first and second lead wires; a second coiled filament extending vertically between and connected to said third lead wire and to the said free end of said auxiliary fourth lead wire; said first and second filaments being spaced apart longitudinally of said reflector axis; a first support wire having one end embedded in said glass bridge adjacent the end thereof near said second lead wire and having its other free end formed to engage and support said first filament approximately at its midpoint; and a second support wire having one end embedded in said glass bridge adjacent the end thereof near said auxiliary fourth lead wire and having its free end formed to engage and support said second filament approximately at its midpoint.

6. A dual beam projector lamp comprising a sealed glass bulb having a concave generally paraboloidal reflector section and a light-transmitting cover glass section and adapted for use with the reflector axis horizontal; said reflector section having three lead wire openings arranged about its apex to be approximately at the corners of a triangle with a first and second of said openings at opposite sides of said apex and in a horizontal plane including said reflector axis and the third opening above said horizontal plane and in a vertical plane including said rcflector axis; metallic thimble members at the exterior of said reflector section having their edges fused in the glass around the margins of respective said openings; first, second and third lead wires having their outer ends anchored in respective said thimbles and projecting through the associated first, second and third openings into the interior of said reflector section; and an auxiliary fourth lead wire connected at one end to the first lead wire and extending laterally therefrom to the said vertical plane including the reflector axis at a point below said horizontal plane with its other free end in alignment with the third lead wire; a rigid insulating glass bridge member extending laterally between and secured at one end to the second lead wire and at its other end to said auxiliary fourth lead wire adjacent its said free end; a first coiled filament extending horizontally between and connected to said first and second lead wires; a second coiled filament extending vertically between and connected to said third lead wire and to the said free end of said auxiliary fourth lead wire; said first and second filaments being spaced apart longitudinally of said reflector axis; a first support wire having one end embedded in said glass bridge adjacent the end thereof near said second lead wire and having its other free end formed to engage and support said first filament approximately at its midpoint; and a second support wire having one end embedded in. said glass bridge adjacent the end thereof near said auxiliary fourth lead wire and having its free end formed to engage and support said second filament approximately at its midpoint.

7. A dual beam projector lamp comprising a sealed glass bulb having a concave generally paraboloidal reflector section and a light-transmitting cover glass section and adapted for use with the reflector axis horizontal; said reflector section having three lead wire openings arranged about its apex to be approximately at the corners of a triangle with a first and second of said openings at opposite sides of said apex and in a horizontal plane including said reflector axis and the third opening above said horizontal plane and in a vertical plane including said reflector axis; metallic thimble members at the exterior of said reflector section having their edges fused in the glass around the margins of respective said openings; first, second and third lead wires having their outer ends anchored in respective said thimbles and projecting through the associated first, second and third openings into the interior of said reflector section; said first lead wire including a fuse section adjacent its outer end with a rigid insulating sleeve spanning said fuse section and closely fitting the lead wire; and an auxiliary fourth lead wire connected at one end to the first lead wire and extending laterally therefrom to the said vertical plane including the reflector axis at a point below said horizontal plane with its other free end in alignment with the third lead wire; a rigid insulating glass bridge member extending laterally between and secured at one end to the second lead Wire and at its other end to said auxiliary fourth lead wire adjacent its said free end; a first coiled filament extending horizontally between and connected to said first and second lead wires; a second coiled filament extending vertically between and connected to said third lead Wire and to the said free end of said auxiliary fourth lead wire; said first and second filaments being spaced apart longitudinally of said reflector axis.

8. A dual beam projector lamp comprising a sealed glass bulb having a concave generally paraboloidal reflector section and a light-transmitting cover glass section and adapted for use with the reflector axis horizontal; said reflector section having three lead wire openings arranged about its apex to be approximately at the corners of a triangle with a first and second of said openings at opposite sides of said apex and in a horizontal plane including said reflector axis and the third opening above said horizontal plane and in a vertical plane including said reflector axis; metallic thimble members at the exterior of said reflector section having their edges fused in the glass around the margins of respective said openings; first, second and third lead wires having their outer ends anchored in respective said thimbles and projecting through the associated first, second and third openings int-o the interior of said reflector section; and an auxiliary fourth lead wire connected at one end to the first lead wire and extending laterally therefrom to the said vertical plane including the reflector axis at a point below said horizontal plane with its other free end in alignment with the third lead wire; a rigid insulating glass bridge member extending laterally between and secured at one end to the second lead Wire and at its other end to said auxiliary fourth lead wire adjacent its said free end; a first coiled filament extending horizontally between and connected to said first and second lead wires; a second coiled filament extending vertically between and connected to said third lead wire and to the said free end of said auxiliary fourth lead wire; said first and second filaments being spaced apart longitudinally of said reflector axis.

9. A dual beam projector lamp comprising a sealed glass bulb having a concave generally paraboloidal reflector section and a light-transmitting cover glass section and adapted for use with the reflector axis horizontal; three lead wires anchored at and arranged about the apex of said reflector section to be approximately at the corners of a triangle with a first and second of said lead wires at opposite sides of said apex and in a horizontal plane including said reflector axis and the third lead wire above said horizontal plane and in a vertical plane including said reflector axis; an auxiliary fourth lead wire connected at one end to the first lead wire and extending laterally therefrom to the said vertical plane including the reflector axis at a point below said horizontal plane with its free end in alignment with the third lead wire; a rigid insulating glass bridge member extending laterally between and secured at one end to the second lead wire and at its other end to said auxiliary fourth lead wire adjacent its said free end; a first coiled filament extending horizontally between and connected to said first and second lead wires; a second coiled filament extending vertically between and connected to said third lead wire and to the said free end of said auxiliary fourth lead wire; said first and second filaments being spaced apart longitudinally of said reflector axis; a first support wire having one end embedded in said glass bridge adjacent the end thereof near said second lead wire and having its other free end formed to engage and support said first filament approximately at its midpoint; and a second support wire having one end embedded in said glass bridge adjacent the end thereof near said auxiliary fourth lead wire and having its free end formed to engage and support said second filament approximately at its midpoint.

10. A dual beam projector lamp as set forth in claim 9 and wherein said first lead wire includes a fuse section adjacent its outer end with a rigid insulating sleeve spanning said fuse section and closely fitting the lead wire.

No references cited.

JAMES W. LAWRENCE, Primary Examiner. 

8. A DUAL BEAM PROJECTOR LAMP COMPRISING A SEALED GLASS BULB HAVING A CONCAVE GENERALLY PARABOLOIDAL REFLECTOR SECTION AND A LIGHT-TRANSMITTING COVER GLASS SECTION AND ADAPTED FOR USE WITH THE REFLECTOR AXIS HORIZONTAL; SAID REFLECTOR SECTION HAVING THREE LEAD WIRE OPENINGS ARRANGED ABOUT ITS APEX TO BE APPROXIMATELY AT THE CORNERS OF A TRIANGLE WITH A FIRST AND SECOND OF SAID OPENINGS AT OPPOSITE SIDES OF SAID APEX AND IN A HORIZONTAL PLANE INCLUDING SAID REFLECTOR AXIS AND THE THIRD OPENING ABOVE SAID HORIZONTAL PLANE AND IN A VERTICAL PLANE INCLUDING SAID REFLECTOR AXIS; METALLIC THIMBLE MEMBERS AT THE EXTERIOR OF SAID REFLECTOR SECTION HAVING THEIR EDGES FUSED IN THE GLASS AROUND THE MARGINS OF RESPECTIVE SAID OPENINGS; FIRST, SECOND AND THIRD LEAD WIRES HAVING THEIR OUTER ENDS ANCHORED IN RESPECTIVE SAID THIMBLES AND PROJECTING THROUGH THE ASSOCIATED FIRST, SECOND AND THIRD OPENINGS INTO THE INTERIOR OF SAID REFLECTOR SECTION; AND AN AUXILIARY FOURTH LEAD WIRE CONNECTED AT ONE END TO THE FIRST LEAD WIRE AND EXTENDING LATERALLY THEREFROM TO THE SAID VERTICAL PLANE INCLUDING THE REFLECTOR AXIS AT A POINT BELOW SAID HORIZONTAL PLANE WITH ITS OTHER FREE END IN ALIGNMENT WITH THE THIRD LEAD WIRE; A RIGID INSULATING GLASS BRIDGE MEMBER EXTENDING LATERALLY BETWEEN AND SECURED AT ONE END TO THE SECOND LEAD WIRE AND AT ITS OTHER END TO SAID AUXILIARY FOURTH LEAD WIRE ADJACENT ITS SAID FREE END; A FIRST COILED FILAMENT EXTENDING HORIZONTALLY BETWEEN AND CONNECTED TO SAID FIRST AND SECOND LEAD WIRES; A SECOND COILED FILAMENT EXTENDING VERTICALLY BETWEEN AND CONNECTED TO SAID THIRD LEAD WIRE AND TO THE SAID FREE END OF SAID AUXILIARY FOURTH LEAD WIRE; SAID FIRST AND SECOND FILAMENTS BEING SPACED APART LONGITUDINALLY OF SAID REFLECTOR AXIS. 